1. Field of the Invention
This invention relates generally to visual and sensor simulation systems and, more particularly, to digital visual and sensor simulation systems useful in providing static or dynamic perspective displays of realistic scenes. These scenes may be of real geographic areas or imaginary areas. For the visual simulation, the eye is the sensor; however, the invention also covers the simulation of infrared (IR) and radar sensor displays. The invention is used to train air (planes, helicopters), sea (ships, submarines), and ground (tanks) personnel. The invention is also used for air, ground or sea mission planning, crew preparation, and crew mission training.
2. Description of Related Art
Current visual and sensor simulation systems process a hierarchy of polygons using hidden surface algorithms on pipelined computer architectures. Polygon data bases are interpolated in real time to generate dense images of picture elements (pixels). Because the data bases of polygon systems tend to be sparse in relation to the data demands, realistic images of actual geographic areas cannot be produced. The processing requirements of polygon systems, using hidden surface algorithms, tends to overload current systems trying to simulate low flight as the viewer looks off at the horizon under clear atmospheric conditions, for the number of hidden surfaces behind each pixel and the number of polygons in the field of view rises very rapidly.
A book entitled Computer Image Generation, edited by Bruce J. Schacter, Copyright 1983, makes reference to three-dimensional data bases. In its various chapters, it treats simulation techniques and training effectiveness. Algorithms and architectures (together with block diagrams of some architectures) used in several computer graphic systems are discussed. Aspects of data-base design in terms of modeling of ground features in the data base to be of the same size, shape, location, color and texture, as the ground features seen by the pilot, are mentioned. Representations of terrains, culture and three-dimensional objects are reviewed. Representations of solids, by octree encoding, algorithmic modeling and the use of second order equations for defining quadric objects are considered. The development of terrain data bases, culture data bases and object/model data-bases is touched upon as are points of consideration in the design of very large scale integration circuits.